A couple of days ago I wrote about the exciting announcement out of NASA that scientists had discovered a lifeform that uses a slightly different set of building blocks than traditional critters.  Specifically, the microbes in question are alleged to use arsenic instead of phosphorus as a component when constructing their DNA. Unfortunately, according to Rosie Redfield, a microbiologist out of British Columbia, the science was sloppy and proves nothing.  Writing on her personal blog, Redfield dissected the Science paper, explaining what the authors did and why it was both inconclusive and misleading. Some excerpts: In Fig. 1 (below), the [... read the rest ...]

One of the most intriguing things about the state of human knowledge is that for all we know about our planet, our solar system, our galaxy, and even the entire universe we haven’t the foggiest idea how it is that we came to be self aware.  The origins of human consciousness are shrouded in mystery, and the best that we can do is speculation. In the December issue of Discover magazine, neuroscientist Antonio Damasio posits twelve steps that may have led to consciousness in living organisms.  Of the twelve, I find the second the most fascinating and poetic: 2. The [... read the rest ...]

I posed this question to readers of my old blog back on January 16, 2006 and I’m still not sure that I have an answer that I’m comfortable with: With the rise of medicine, humans with otherwise debilitating or fatal health problems have been able not only to survive, but to propagate their genetic weakness throughout the species.  Will the human capacity for innovation, as embodied by medicine, actually end up being a sort of genetic Achilles’ heel?  If we are not able to purge weakness using the gene pool, as we have for millennia, are we on a course [... read the rest ...]

The SETI Institute – an organization devoted to the Search for Extraterrestrial Intelligence – has always been something of an enigma to me.  One one hand, they seek to answer one of the fundamental questions of human existence, Are We Alone?, but on the other their methods seem far too anthropomorphic and to narrowly focused on technology that was developed in an interstellar eye blink. As pointed out on the Discover blog, SETI astronomer Seth Shostak recently mused in Acta Astronautic that the organization should refocus its efforts and start searching for signs of artificial intelligence instead of the sloppy [... read the rest ...]

The September issue of Discover magazine contains an article (online version not yet available) about a puzzling bit of human evolution:  the human brain has been shrinking at what some scientists consider an alarming rate, and no one understands why or what the ramifications might be. Over the past 20,000 years, the average volume of the human male brain has decreased from 1,500 cubic centimeters to 1,350 cc, losing a chunk the size of a tennis ball.  The female brain has shrunk by about the same proportion.  “I’d call that a major downsizing in an evolutionary eyeblink,” [anthropologist John Hawks] [... read the rest ...]